Floor-jack



A. KEHOE FLOOR-JACK 2 Sheets-Sheet 1 Filed Aug. 10, 195

INVENTOR (Id/7766 I). K 6/109 M {Z 6% ATTORNEY J. A. KEHOE May 27, 1958 FLOOR-JACK 2 Sheets-Sheet 2 Filed Aug. 10, 1956 INVENTOR James A. Kehoe ATTORNEY nite States Patent FLOOR-JACK James A. Kehoe, Maysville, Ky.

Application August 10, 1956, Serial No. 603,261

11 Claims. (Cl. 254-12) This invention relates to a jack for exerting pressure on external elements and more particularly to construction jacks adapted to engage a supporting surface, such as a joist or beam, and adapted to exert pressure on another external element, such as a wooden floor board, roof sheeting, railroad rail, or the like, and clamping it firmly in position until released.

The laying of wooden flooring, roof sheeting, and the like, has involved considerable skill to provide good tight joints between boards. Often a carpenter finds it necessary to exert considerable force against a board, which may be slightly warped, in order to close the joint between adjacent boards. It is not unusual in such a situation for a carpenter to rap a board into place and then to nail it down. This has two undesirable features. In rapping the board into place, it often is damaged so that the floor surface is marred. In addition, it often happens that the board springs back, at least slightly, before it is nailed down, and the joint then is not as tight as it should be. in laying rails and the like, it is necessary that a very accurate positioning of each rail be made in order to assure maximum safety, minimum repairs, and long life and smooth operation of the equipment.

The present invention is directed to a jack which is easy and quick to operate for exerting just the correct ressure to place the board, rail, or other element in its proper position and to hold it in that position, without further attention, until the board or rail has been nailed or otherwise secured in place. This improved jack leaves both the users hands free for fastening the board or other element, while securely clamping it exactly as desired without damaging any part of it. The pressure bar of the jack may even be provided with a grooved pressure end for more effectively engaging the tongues of tongued boards.

A jack made in accordance with this invention includes only three simple members. One is a clamp member formed of a pair of relatively movable jaws connected to a hand grip for conveniently placing them around a supporting element. The second is a pressure bar member for transmitting and applying pressure on the element to be pressed into position. The third is the operating handle member which is operatively connected to both the clamp jaws and the pressure bar through a gear which actuates the pressure bar by a gear rack and simultaneously operates the clamp jaws by a special screw thread pressure means. A simple pull on the handle towards the element to be biased, exerts pressure on the element and simultaneously proportionately tightens the clamping of the jaws on the supporting element to prevent slippage. Release of the handle locks the pressure bar in place by engagement of a simple curved surface on the pressure bar by a locking finger on the handle and prevents slipping of the clamped element, thus freeing both hands for use in securing the element in position. Removal of the jack is a correspondingly simple operation. It is merely necessary to move the handle in a direction away from the element pressed into place, thereby releasing pressure upon it and of the clamp jaws on the suporting element, and to lift the jack from its supporting element by the hand grip. This jack thus greatly facilitates the proper laying of flooring and sheeting, the placement of rails, and other such operations.

An object of this invention is to provide an improved and simplified jack.

Another object of this invention is to provide an improved flooring jack with an improved and simplified supporting clamping structure.

A further object of this invention is to provide an improved jack with a pressure member and a supporting clamping member simultaneously operable to vary the support clamping pressure with the pressure exerted by the pressure bar member.

A still further object of this invention is to provide an improved jack with an improved and simplified lock for locking the pressure bar member in position on release of the operating handle.

Further objects and advantages of this invention. will become apparent upon an understanding of the following description of the illustrative embodiment or will be indicated in the appended claims, and the features of novelty which characterize this invention will be pointed out with particularity in the claims appended to and forming a part of this specification.

A preferred embodiment of the invention is illustrated in the drawings, described in this specification and forming a part thereof, wherein:

Fig. 1 is a perspective view of an embodiment of an improved jack made in accordance with this invention and shown applied to a floor joist and a' tongued iioor board;

Fig. 2 is a side elevational view of the jack shown in Fig. 1, showing in dotted lines details of the gear rack drive and lock for the pressure bar, which is shown partly broken away;

Fig. 3 is an end elevational view of the jack in Figs. 1 and 2;

Fig. 4 is a fragmentary enlarged detailed View gear rack drive and lock for the pressure bar, in dotted lines in Fig. 2;

Fig. 5 is a fragmentary end elevational view, partly broken away, of the operative connection of the handle to the pressure bar through the gear and rack and to the clamp jaws through the screw thread tightening arrangernent, in the jack shown in the other figures of the drawings; and

Fig. 6 is a fragmentary exploded perspective view of the details of the operative connection of the handle to the pressure bar and clamp jaws, shown in Fig. 5.

Referring to the drawings, this invention is illustrated embodied in a carpenters jack, applied, in Fig. l, to a tongue-and-groove type flooring. The jack is formed with a clamp member for securing it to an external supporting element and is comprised of a substantially U- shaped clamp with a base 1 forming a hand grip for holding the jack in position While operating it and for facilitating general handling of the jack. This clamp is formed with a pair of legs 2 and 3, which extend from the hand grip base 1, and one clamp leg 2 is longer than the other, so that the outer end 2' thereof forms one of the jaws of the clamp. A cooperating and relatively movable clamp jaw 4 is pivotally mounted by a pin 5 on the outer end of the other leg 3 in a position substantially parallel to the longer leg jaw 2' and swingable toward and away therefrom. In order to assure a good grip by the pair of jaws 2' and 3 on a supporting element, such as a floor joist 6, when arranged in clamping engagement therewith, as shown in Fig. 1, the inshown of the shown tate its operation.

ner surface of'each jaw'pr eferably is provided with a 'pluralityof rows *ofspaced relatively shallow cleats oi" gripping elements 7. These cleats 7 are used to secure the jack in positioniand dosnot engage the flooring, so that they in noway ,damage the flooring boards, and

are adapted to be clamped into the sides of the floor joist 6 by an'easily operatedsimple threa ded tightening rod and handle structure. v 1

As is more clearly- 's hown in Figs. 3, 5, and 6, the

clamp tightenin'gnstructure comprises a tightening rod '8 which extends through substantially aligned apertures 'If desired,

9 and in the jaws 2'; and 3, respectively. p the aperture 9 through the jaw 2 may beth'readedand the end of 'thestightening rod.8 maybe threadedly secured therein at 11, Withla locknut '12 fastened on the outer end ,ofthe rod, thus assuring against accidental loosening of the tighteningrodL The aperture 10 through the jaw 3 is slightly larger than the tightening'rod so as to allow a clearance around the rod to provide for free swinging of the jaw 3 toward and away from the jaw 2"without binding on the tightening rod. The end of the rod adjacent to the jaw 3 is threaded at 13 and is formed with arelatively short, smaller diameter, threaded hub 14 on the end thereof for engagement with 'a nut 15 for securing the entire assembly together.

An operating handle structure is provided to cooperate with the tightening rod for securing the jack in 7 ternal gear teethj27, as a gear ' the internally "threaded spur gear 19, which is wide enough to' span both the handle gear teeth 18and the pressure bar gear rack teeth 27.' The width of the slot" is such that its lower edge is clear of the, gear 19, and a U-section guide cover 28 is arranged overgthe pressure bar, covering the slot 26 and formed withan; l:

aperture therein whichfits over thetightening rod hub 14, so as slidably to guide'and operatively to secure the pressure bar in driving engagement 'with the spur gear 19 and through it to the 'handle 16 and the tightening rod 8. The nut 15 is adapted to be'drawnup tightly on the threaded hub 14 and against a lockwasher 29, so as securely to fasten the guide cover 28 against the shoulder, whererthe hub 14 joins the threaded portion 13 of the tightening rod. This assures a "secure assembly of the relatively movable operating parts of the jack and provides for moving the pressure bar forwardly to exert'pressure or rearwardly to release the pressure,while simultaneously and correspondingly'moving thejclamp jaw 3 respectively toward and away from s the jaw 2 for tightening andloosening its grip on the position on the joist- 6.@This operating handle struc 'ture preferably includes a' relatively long straight handle bar '16 which provides goodleverage for'ease in operating the jack, and any suitable hand grip 17 may 7 19 is internally threaded and threadedly engages the end 13 of the tightening rod 8 for longitudinal movement along the threaded portion 13 of the tightening rod.

In operation, the spur gear 19 is adapted to be screwed on-the tightening rod until it engages thevouter surface of a large spacing washer 20 adjacent the jaw 3. This washer 20 is arranged to fit loosely over the shank of the tightening bar between the handles16 and spur gear 19 and the jaw 3 so as to minimize the friction'therebetween. In this manner a turning of the handle 16 turns the spur gear 19 and screws it longitudinally along the tightening rod toward and away from the hinged jaw 3 for correspondingly pressing against and moving the jaw 3 relative to the longer clamp leg 2 and jaw jaws on the supporting joist 6. 7

As previously stated, the illustrated carpenters jack is adapted to exert pressure on tongue-and-groovefiooring boards 21 for biasing them into tight engagement with adjacent'boards for providing tight joints therebetween The biasing together of the boards 21 is done by a simple application of pressure on the tongue 22 of the board 21 which is being nailed in place. This pressure is adapted to be applied bythe jack through pressure bar 23, preferably formed with a pressure head comprising a wedge-shaped element 24, suitably set-'1 end ofthe bar' 23 opposite the pressure head. The supper longitudinal edge of this slot, 26 is formed with insupp'ortingjoist 6, by the simple movement of the handle 16 toward and away from the working pressure a head of the pressure bar. g

In a'jack of the type illustrated, it is necessary that' the jack' be locked in its pressure position, so that the carpenters hands will be free toenail the board after it has) been pressed into position; This locking'o-f the pressure bar isobtained :by formingra curved locking surface 30 on the end of the pressure bar-adjacent to the slot 26,

which is adapted to engage a locking finger 31 on the adjacent internal gear end of the handle 16. The finger 31* is formed with an outturned locking end 32' which is extendable over the curved surface 30 of the pressure "bar, so. that when'the handle 16 is released, the back pressure of the board 21 on the pressure bar 23 and the slack in'the mesh of therack teeth 27 with the spur gear 19 provides for .a slight release movement of the pressure bar causinga lockingengagement of the surface 30' with the end 32 of the finger-31 which loclts-the pressure bar imposition. Since the pressure bar moves longitudinally 2' and respectively tightening and loosening the clamp Cal away from the lockingfinger 31 as the handle 16 is turned in a direction which moves the locking finger 31 from adjacent the lower side 33 of the pressure bar towards the upper or gear rack side'34 of the pressure bar, it is necessary that the curveof the locking surface 39 be an involute of the circle which measures; the ad-, vance 0f:the pressure bar. This circle is that of the radius of therspurr gear 19 which drives the pressure bar. The curve of the surface 30 is such that there is' just a slight clearance between the locking end 32 of the finger 31 and the surface 35 at a point when the handle 16 is turned to place the finger end 32 adjacent to the outer corner 35 of the curved locking surface 30 opposite the toothed side of the pressure bar slot 26. In order; to provide the desired locking engagement of the surface 39 with the finger end 32, the curve of the surface is formed as the involute of the spur gear added to the length of a tangent to the spur gear passing through the outer corner 35 as is more clearly shown in Fig. 4. This assures a slight clearance between the locking surface 30 and'the finger end 32 for all positions of the finger adjacent to the surface, so asto assure the automatic locking of the pressure bar in position on release of the handle 16. a 7 7 7 Positive turning of the handle away from the work' turns the spur gear 19 in a direction which simultaneously retracts the pressure bar 23 and loosens the grip of the clamp jaws2' and 3, and provides for the simple removal of the jack to another position.

The "present invention provides a jack which is simple in structure and is easily operable by the turning-of a single handle, which automatically locks the pressure bar rack, which mesh with i in position on release of the handle and frees both hands of the operator for other work.

A particular embodiment of this invention has been disclosed herein and various changes in form, structure, and arrangement may be made therefrom without departing from the spirit and scope of this invention; it is to be understood, therefore, that all matter herein is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws, means including a spur gear operatively engaging said tightening rod for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an end of said pressure bar, a longitudinally extending rack on said pressure bar arranged in mesh with said spur gear, and an operating handle member comprising a handle with an internal gear therein with teeth complementary to said spur gear and arranged in mesh therewith for turning said spur gear by turning said handle whereby said spur gear is longitudinally movable relative to said tightening rod toward and away from said jaws for correspondingly moving said jaws relative to each other and correspondingly operating said pressure bar rack for moving said pressure bar end transversely relative to said tightening rod for thereby respectively exerting and releasing pressure on said other external element.

2. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws and having a threaded portion, means including an internally threaded spur gear threadedly engaging said tightening rod threaded portion for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an end of said pressure bar, a slot in said pressure bar formed with internal gear teeth as a rack along one longitudinal edge thereof as a rack arranged in mesh with said internally threaded spur gear, and an operating handle having a driving connection with said internally threaded spur gear for turning said spur gear by turning said handle whereby said spur gear is longitudinally movable along said threaded tightening rod toward and away from said clamping jaws for correspondingly moving said jaws relative to each other and correspondingly operating said pressure bar rack for moving said pressure bar end transversely relative to said tightening rod for thereby respectively exerting and releasing pressure on said other external element.

3. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws, means engaging said tightening rod for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an end of said pressure bar, means operatively connecting said pressure bar with said means for drawing said jaws toward each other, a curved locking surface on the end of said pressure bar opposite said first mentioned end thereof, and a handle operatively connected to said means for drawing said jaws toward each other for moving said jaws toward and away from each other and for moving said pressure bar curved locking surface end transversely relative to said tightening rod for respectively exerting and releasing pressure on said other external element, and a locking finger on said 6 handle with an outturned locking end extendable over said locking curved end surface on said pressure bar for locking said pressure bar in position on release of said handle.

4. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws and having a threaded portion, means including an internally threaded spur gear threadedly engaging said tightening rod threaded portion for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an end of said pressure bar, a gear rack on said pressure bar arranged in mesh with said internally threaded spur gear, a curved locking sur face on the end of said pressure bar opposite said first mentioned end thereof, and a handle operatively connected to said internally threaded spur gear for turning said spur gear by turning said handle whereby said spur gear is longitudinally movable along said threaded tightening rod toward and away from said jaws for correspondingly moving said jaws relative to each other and said pressure bar curved locking surface end transversely relative to said tightening rod for respectively exerting and releasing pressure on said other element, and a locking finger on an end of said handle adjacent to said internal gear therein with an outturned locking end extendable over said locking curved end surface on said pressure bar for locking said pressure bar in position on release of said handle.

5. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws and having a threaded portion extending through and outside one of said jaws, means including an internally threaded spur gear threadedly engaging said tightening rod threaded portion for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an end of said pressure bar, a slot in said pressure bar formed with internal gear teeth as a rack along one longitudinal edge thereof arranged in mesh with said internally threaded spur gear, a curved locking surface on the end of said pressure bar opposite said first mentioned end thereof, and an operating handle member comprising a handle with an internal gea therein with teeth complementary to said internally threaded spur gear and arranged in mesh therewith for turning said spur gear by turning said handle whereby said spur gear is longitudinally movable along said threaded tightening rod toward and away from said clamping jaws for correspondingly moving said jaws relative to each other and correspondingly moving said pressure curved locking surface end transversely relative to said tightening rod for respectively exerting and releasing pressure on said other external element, and a locking finger on an end of said handle adjacent to said internal gear therein with an outturned locking end extendable over said locking curved end surface on said pressure bar for locking said pressure bar in position on release of said handle.

6. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws and having a threaded portion, means including an internally threaded spur gear threadedly engaging said tightening rod threaded portion for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an endof'sa'id pressure bar,

"a gear rack on said pressure bar arranged in mesh with said internally threadedspur gear, means for slidably guiding and operatively securing said pressure bar in mesh with said spur geareand to said tightening rod, "and an operating handle member comprising a handle with an internal gear therein with teeth complementary to said internally threaded spur gear-and arranged in mesh therewith for turning said spur gear by'turning said handle whereby said spur gear is longitudinally movable along said threaded tightening rod toward and awayfrorn said jaws for correspondingly moving said jaws relative to each other and said pressure bar end transversely relative to said tightening .rod for thereby respectivelyexertingand releasing pressure onsaidother external element, and -means for locking saidpressure bar in position on release of said handle. I

7. A jack including a member for securing the jack in operative position, said member comprising a substantially U-shaped clamp with a base forming a hand grip and a pair of legs extending therefrom, one of said legs being longer than the other andhaving an inner 'face with gripping elements thereon adjacent to the outer end thereof, a clamping jaw having an inner face with gripping elements thereon, means pivotally connecting said jaw to the, end of said other leg substan-:

tially parallel to said longerleg and swingable toward and away therefrom, a tightening rod extending be ween said longer leg and said jaw and having a threaded portion, means including an internally threaded spur gear threadedly engaging said tightening rod threaded por-' tion for drawing said jaw toward said longer leg in clamping engagement against an element arranged therebetween and for loosening such clamping engagement,

at pressure member comprising a pressure bar for engaging another element against which pressure is to be exerted by an end of said pressure bar,'a gear rack on said pressure arranged 'inmesh withsaid internally threaded spur gear, and an operating handle member comprising a handle operatively connected to said spur gear for turning said spur gear by turning said handle whereby said spur gear is longitudinally movable along said threaded tightening rod toward and away from said clamping jaw for correspondingly moving said jaw relative to said longer clamp leg and said pressure bar end said "other external elemenhand means for locking said pressure bar in position on lreleaseeof said'handle;

'9. A jack fincludinga member for securing-thejack in operative position, said member comprisingia substantially U-shaped clampwith aibaseiforming a hand gripjand a pair of legs extending therefrom, one of said legs being longer than the' otherand having an innerface .With gripping elements .thereont'adjacent'tto: the outer end thereof,

a clamping jaw having aninner' face with gripping elements thereon, means'pivotally connecting said jaw to the end'ot said other leg substantially parallel :to said longer .leg:and 'swingable toward and awaytherefrorma tightening rod extending between said glonger leg and" said jaw and having a threaded portion, means includingan internally threaded spur gear fthreadedly engaging said tightening rod'thre aded portion for drawing-said jaw toward said longer leg in 1 clamping engagement against 7 an external elementarrangedi therebetween andjorlooseuing such clamping engagement, a pressure member for engaging another external element, saidpressure member having a :ra'ck arranged in mesh with said internally threaded spur gear, 'andjan operatinghandle member comprising ahandle with an internal gear therein with teeth complementary to said internally threaded spur,

inversely transversely relative to said tightening rod for respectively exerting and releasing pressure on said other element. 7 a V 8. A jack including a member for securing the jack in operative position, said member comprising a pair of jaws pivotally connected together, a tightening rod extending between said jaws and having'a threaded portion, means including an internally threaded spur gear threadedly engaging said tightening, rod threaded portion for drawing said jaws toward each other in clamping engagement against an external element arranged therebetween, a pressure member comprising a pressure bar for engaging another external element against which pressure is to be exerted by an end'of said pressure bar, a slot in said pressure bar formed with internal gear teeth as a rack along one longitudinal edge thereof arranged in mesh with said internally threaded spur gear, means in cluding a gmide cover over said pressure bar slot for slidably guiding and operatively securing said pressure bar in mesh with said spur gear and to said tightening rod, and an operating handle member comprising a handie with an internal gear therein with teeth comple menta'ry to said'internally threaded spur gear and ar-' ranged in'mesh therewith for turning said spur gear by turning said handle whereby said spur gear is longitudinally' movaolc along said threaded tightening rod toward and away from said jaws for'correspondingly moving said jaws relative to each other and'said pressure bar end transversely relative to saidtigh'tening rod for thereby respectively exerting and releasing pressure on gear and arranged in mesh therewith for turning said Ispur gear by turning said handlewhereby said spur gear is; longitudinally movable alon'g saidthreaded tightening rod toward ;and away fron'rsaidclanrpingjaw for correspondingly moving said jaw relative to said longer clamp leg and said pressure'bar; end inversely transversely relative to said tightening rod for respectively exerting and with said internally threaded spur ge ar, a curved locking surface on't the end of said; pressure bar: opposite, said first mentioned endformed-as the involute of the circle of the radius of said internally threaded spur gear added to a predetermined lengthequal to the length ofatangent to said internally threaded spur gearpassing through the outer corner of said curved end of said pressure bar on the side thereo'f opposite to said toothed side of said slot with said pressure barin meshed position with said spur gear, and an operating handle with an internal'ge ar therein havingteeth complementary to said internally threaded spur gear and arranged in mesh therewith for turning said spiur gear by turning said handlejwhereby said spur gear is longitudinally movable ,along vsaid threaded tightening rod toward and" awayorrom said clamping "jaws for "c:or respondingly moving said jaws relative to each other and correspondingly moving 1 said pressure 'bar curved end transversely relative to said tightening rod, anda locking finger on anend .of said handle adjacentto saidinternalgeat therein with.an out- 7 turned locking-end .extendableoveisaid locking'curyed end surface on said pressurekban .wherebyslackin the 'mesh of saidracl; teeth with said spur. gear, provides, for

a slight release, movement of said pressure bar on release of said handle c'ausin'g'a'locking engagementjof 's'aid pressure bar curved end surface withfsaid lockingfingerand locking of saidpressure bartintposition, r I

ll. A jacl including asmember-for securing the jack in operative position, "said member comprising a substantially U-shapedclamp with a base forming a hand grip and a pair of legs extending. therefrom, one of said legs beinglo'ng'er than the other an'd forming a 'jaw withlau inner face having gripping elements thereon adjacent to the outer end thereof, a clamping jaw having an inner face with gripping elements thereon, nieans pivotally conmeeting said clamping jaw to the end of said other leg substantially parallel to said outer end of said longer leg and swingable toward and away from said longer leg, coaxial apertures in said longer leg and in said clamping jaw adjacent to said pivotal connecting means, a tightening rod extending through said apertures having a threaded portion extending outwardly beyond one of s tures, means including an internally threaded spur gear threadedly engaging said tightening rod threaded portion for drawing said clamping jaws toward said longer leg in clamping engagement against an external element, a pressure member having a grooved end thereon for engaging another external elernent against which pressure is to be exerted, a slot in said pressure member extending longitudinally thereof adjacent to the end opposite said grooved end and formed with internal gear teeth as a rack along one longitudinal edge thereof arranged in mesh with said internally threaded spur gear, means including a U-section guide cover over said pressure bar slot for slidably guiding and operatively securing said pressure bar in mesh with said spur gear and to said tightening rod, and an operating handle member comprising a handle with an internal gear therein with teeth complementary to said internally threaded spur gear and arranged in mesh therewith for turning said spur gear by turning said handle whereby said spur gear is longitudinally movable along said threaded tightening rod toward and away from said clamping jaw for correspondingly moving said jaw relative to said longer clamp leg and said pressure member end transversely relative to said tightening rod for thereby respectively exerting and releasing pressure o: said other external element.

References Cited in the file of this patent UNITED STATES PATENTS 364,794 Bradley June 14, 1887 

